# TOHNICHI power torque tools tighten screws accurately when they

```How to Use
TOHNICHI power torque tools tighten screws accurately
when they are used correctly.
■ Calculating the compressor capacity.
Power Torque Tools
The compressor capacity necessary to drive a power torque tool can be determined by the
volume of air required to tighten each screw (m&sup3;/piece) and the number of screws requiring
tightening (piece/h). Provide some allowance, however, for leakage and future system
expansion.
1
Volume of air ＝ Volume of air required to &times; Number of screws to &times; Thread ratio&times; 60
tighten each screw
be tightened
consumption
[m&sup3;/min]
[m&sup3;/piece]
[Piece/h]
Volume of air required to tighten each screw : Volume of air (standard air) necessary for tightening one
screw (number of threads tightened = 10). Values are
given in the specification column for each tool.
Number of screws to be tightened : Number of screws to be tightened per hour.
Thread ratio : The number of threads to be tightened divided by 10, the standard number of threads.
For example, when the number of threads is 6, the ratio is 0.6.
Example:
When four thousand M5 screws (number of threads: eight) are to be tightened using several U500CN tools.
(volume of air required to tighten each screw: 0.0031 [m&sup3;/piece])
1
Volume of air consumption =0.0031&times;4000&times;0.8&times; [m&sup3;/min]
60
=0.165 [m&sup3;/min]
Compressor output
=0.165&times;6.5 [kW]
=1.07 [kW]
(The motor output necessary for the compressor to discharge 1 [N] is 6.5 [kW] at a
gauge pressure of 0.7 [MPa])
Cost of tightening power
=0.0031&times;4 [yen/piece]
=0.0124 [yen/piece]
(Cost of compressed air is 4 [yen/piece] at a gauge pressure of 0.7 [MPa], including
the costs of electricity, compressor depreciation, etc.)
346
TOHNICHI TORQUE HANDBOOK Vol.8
```